New South Wales Premier Mike Baird has been criticised for not mentioning tough new counter-terrorism laws at a meeting with Muslim community leaders held in Sydney, hours before the announcement.

Mr Baird and NSW Police Minister Troy Grant announced on Monday night they had written to Prime Minister Malcolm Turnbull pushing for tougher national security laws in the wake of the fatal shooting at NSW Police Headquarters at Parramatta on October 2.

But Silma Ihram from the Muslim Women's Association said community leaders, including the Grand Mufti of Australia and the chairman of Parramatta Mosque, should have been briefed about the plan when they attended a meeting at the Premier's office in Sydney just hours earlier.

"I think it's very unfortunate. When you go to consultation, you expect there's going to be the opportunity to hear what the Government's going to do before they do it," Ms Ihram said.

"It certainly took us by surprise, especially since they were announced shortly after the meeting.

"We don't believe they are going to be beneficial to Australian society as a whole and it certainly is going to feed straight into the narrative of Daesh (another name for Islamic State)... so it's really a major problem and it's going to make things worse, unfortunately."

Ms Ihram said the proposals would not have been well received by Muslim leaders at the meeting.

"I think if they'd bought it up... there would have been such a reaction that the meeting would have gone into absolute chaos, because we were already stating how the securitisation is already having such a negative effect on the community," she said.

The proposed measures include subjecting teenagers as young as 14 to control orders and increasing the length of time that terror suspects can be detained without charge.

Reform needs 'firm legal and logical basis'

NSW Opposition Leader Luke Foley, who attended the meeting, also questioned why the new proposals were not mentioned.

"I do have to say I'm surprised that it was raised after yesterday's meeting, not at the meeting or before it," Mr Foley said.

Mr Foley said he supported lowering the age for control order but had reservations about extending the period that people could be held without charge.

"I don't think governments should simply enact new measures just to be seen to be doing something," he said.

"There has to be a firm legal and logical basis for such a reform – and I'm yet to hear it," he said.

Former NSW director of public prosecutions Nicholas Cowdery went further, questioning the need for new terrorism laws at all.

"We don't need more laws. We already have more in this area than any other developed western country," Mr Cowdery said.

"We need to be very careful to balance appropriately the measures adopted for public protection and the human rights of members of the community in the laws enacted and in the way they are enforced."

Mr Baird said the events in Parramatta 11 days ago showed the changes to the legislation are necessary.

"Our police must have the powers they need to hunt down those that are determined to take away our values and freedoms, that are determined to take away innocent lives," he said.

"They can't have that. And that's why we need to respond to our police and the request for these powers."

Mr Grant also defended the timing of the announcement.

"Yesterday wasn't the time or place to have that conversation," he said.